Telephone-switch.



Patented Oct. l6, I900.

A.- STBOMBEBG.

TELEPHONE SWITCH.

(Application filed June 13I 1900.)

(No Model.)

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ALFRED STROMBERG, OF CHICAGO, ILLINOIS.

TELEPHONE-SWITCH.

SPECIFICATION forming part of Letters Patent No. 669,940, dated October 16, 1900.

A li ati n filed June 13, 1900, Serial. No. 20,129. (No model.)

To to whom it nuty concern:

Be it known that I, ALFRED STRoMBERe, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Telephone-Switches, (Case No. 8,) of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to telephone-switches, and has for its object the provision of an improved form of gravity switch-hook for use at subscribers stations.

My invention has for one of its objects the provision of an improved form of gravity switch-hook wherein those parts that are frequently subject to changeable engagement are relieved of excessive friction and whereby a positive actuation of circuitchanging spring portions is secured.

By means of my invention I have been able to employ stiff springs as circuit-changing means, which may be readily actuated through the agency of a switchhook constructed in accordance with my invention.

In the preferred embodiment of my invention the receiver supporting the hook is electrically distinct from the switching appara tus, the switch-hook being preferably in the form of a bel1-crank lever hinged at its elbow to a suitable support. bell-crank extends horizontally and is provided with a hook for supporting a receiver at its free end. The remaining arm of the bell-crank is preferably much shorter and extends vertically from the pivotal mounting of the bell-crank. This shorter arm of the bell-crank is provided with a roller-contact, preferably in the form of a cylinder of insulating material, that is adapted for engagement with circuit-changing springs, the roller in changing its points of engagement with the springs serving, as the bell-crank is actuated, to effect and permit changes in the circuit condition of the instrument or appara- A coiled spring preferably surrounds the shaft where the switch-arm is pivoted, one end of the coiled spring engaging the switch-hook mounting, while the other end engages a pin upon the switch-hook, the coiled One arm of the,

spring serving to lift the horizontal arm of the bell-crank when the receiver is removed.

I will explain my invention more fully by reference to the accompanying drawings, in which Figure 1 is a rear view of a switch-hook and containing case constructed in accordance with my invention. Fig. 2 is a sectional view thereof on line 2 2 of Fig. 1. Fig. 3 is a top View, partially in section, of my improved switching mechanism; and Fig. i is a diagram matic view illustrating the electrical con nections.

Like parts are indicated by similar characters of reference throughout the dilferent figures.

The telephone-switch hook is preferably in the form of a bell-crank lever, having a long horizontal arm a, provided with a hook Z) for supporting the receiver. The switch-arm c is preferably placed substantially at right angles with relation to the arm a and is bifurcated at its lower end to receive a roller cl,coustructed, preferably, of insulating material. Two springs e andf are adapted for mechanical engagement with the roller, each spring being provided with an incline, through the agency of which and the engaging roller they are depressed from contact-springs g and 7L when the longer arm of the bell-crank is depressed through the agency of the receiver when carried thereby. When the bell-crank is relieved of the weight of the receiver, the coiled spring i and the springs e and f serve to lift the long arm of the bell-crank, thereby permitting the springs e and f to engage the contacts g and h.

The telephone-switch hook is shown as being applied to a battery transmitter, the springs e and fserving, upon their engagement with the contacts 9 and h, to close circuit through the transmitter with its battery and through the telephone-recei V61,'Cl18 spring fupon its elevation being at the same time removed from engagement with the lower contact 70, which constitutes the terminal of a signaling-circuit, the spring f being brought into engagement with this terminal when the receiver is restored, circuit through the transmitter and receiver being at the same time open.

I have illustrated casing Z that contains the induction-coil, the mounting for the receiversupporti'ng arm, and the switch parts. A swinging arm m is provided upon the front of the casing Z and supports a suitable form of transmitter.

I have thus devised an improved form of switch-supporting lever-arm that is capable of effecting the actuation of stiff springswithout any appreciable frictional wear. The switch-arm is free of electrical connection.

Changes may readily be made from the preferred embodiment of my invention herein shown and particularly described, and I do not, therefore, wish to be limited to the precise construction shown but,i

Having thus described my invention, I claim as new and desire to secure by Letters Patent- In a telephone-switch, the combination with 1 a bell-crank lever, provided with. a long arm having a hook for holding the receiver and a short arm, of a roller provided upon. the free end of the short arm, contact springs e and f 1 provided with sloping portions for engagement with the roller, one of said contactsprings being connected with one side of the telephone-line, while the other constitutes a terminal of a transmitter-circuit, contacts 9 andh located above the contact-springs e and f, one of said contacts constituting a terminal of the branch including the receiver, while 5 the other constitutes the remaining terminal of the transmitter-circuit, and a lower contact k adapted for engagement with the conf tact-spring that is connected with the line when the said spring is depressed through the agency of the receiver, the latter spring also engaging the contact-terminal of the receiver when elevated upon the removal of the telephene reeeiver, substantially as described.

In witness whereof I hereunto subscribe my name. this 8th day of June, A. D. 1900.

ALFRED STROMBERG. Witnesses:

MAX W. FABEL, GEORGE L. CRAGG. 

